Peshawar (Pakistan) (AFP) - Taliban gunmen stormed an army-run school in restive northwest Pakistan on Tuesday, killing at least three students and triggering a standoff with troops, officials and militants said.
The militants have been ordered to shoot older students, a Taliban spokesman said, adding the attack was revenge for a major military offensive.
At least five insurgents wearing military uniforms have entered the Army Public School in the city of Peshawar, a source at the school told AFP.
A senior military official said troops had surrounded the school and television footage showed them taking up positions.
Sharif Khan, a doctor at Peshawar's Lady Reading Hospital, told AFP they had received 35 wounded, two of them teachers, as well as the bodies of three students.
A senior police official confirmed the death toll and warned it was likely to rise, saying a "huge blast" had occurred inside the school.
The Tehreek-e-Taliban Pakistan (TTP) claimed responsibility for the attack, saying it was retaliation for the army's continuing operation against militants in the North Waziristan tribal area close to Peshawar.
A senior military official told AFP that troops had cordoned off the area around the school and were hunting down the militants.
The school on Peshawar's Warsak Road is part of the Army Public Schools and Colleges System, which runs 146 schools nationwide for the children of military personnel and civilians. Its students range in age from around 10 to 18.
The schools educate the children of both officers and non-commissioned soldiers and army wives often teach in them.
A security official told AFP that hundreds of students and staff were in the school when the attack began, though it was not immediately clear how many are still being held.
TTP spokesman Muhammad Khorasani told AFP there were six attackers.
"They include target killers and suicide attackers. They have been ordered to shoot the older students but not the children," he said.
"This attack is a response to Zarb-e-Azab and the killing of Taliban fighters and harassing their families."
Zarb-e-Azb is the official name for the army's offensive against strongholds of the Taliban and other militants in North Waziristan.
The offensive has killed more than 1,600 militants, according to an AFP tally.
The military has hailed the operation as a major success in disrupting Taliban militancy.
The semi-autonomous tribal areas that border Afghanistan have for years been a hideout for Islamist militants of all stripes -- including Al-Qaeda and the homegrown TTP as well as foreign fighters such as Uzbeks and Uighurs.
Washington pressed Islamabad for years to wipe out the sanctuaries in North Waziristan, which militants have used to launch attacks on NATO forces in Afghanistan.